1. Expensive, and is federal not just CA. Who do you think imposed the emissions requirements on the mfgs? Some states are simply enforcing what has been the law for a long time.

2. It depends if you're willing to chance paying for a more expensive repair out of pocket since your warranty is going out the window.

3. Most likely not any major increases.

Bottom line, you bought a large truck and then lifted it sky high with big tires. What else were you expecting? If you are that concerned with mpgs then sell the truck and get something more economical and leave it stock. You're looking at maybe 5mpg difference and I doubt you'd even see that much. I'd leave it stock until the warranty is up since repairs to that engine are costly. Once the warranty is gone then I'd think about it. The biggest key to keeping the fuel numbers up on the 6.4L is keeping the rpms down and running as unloaded as possible. Both are hard to do with that engine, and your lift/tires makes it even harder. I've heard of guys getting near 20mpg in stock form with the dpf delete.

On my gasser I never saw an increase in MPG's with an intake and exhaust even when those were my only mods, definitely never saw an increase after custom tuning either... Sorry I can't say for diesels though I have heard good things about the DPF delete and spartan tunes..

I wouldn't really worry about getting caught, just keep it and put it back on for inspections. How would they catch you on an everyday basis anyway? I know they are strict in CA but geez pulling you over just to check the exhaust

I would talk to innovative diesel. Check out thier website, IIRC you will have to sign a waiver for anykind of deleting you do stating you know the modifactions made to the truck make it illegal for street use.

I live in florida so I've never had to deal with any emissions law BS so I can't really give you any input on that. But I will tell you that if you just run a straight pipe and proper tuning(SCT/Spartan) you WILL see DRASTIC power gains and improved mpg. And like every one has already mentioned, can't really buy a 8000lbs crew cab 4x4 and and lift it then expect to get good mpg.

I've done the delete with a spartan on a f350. Mileage went up to an average on 16 and thats driving the hell out of it. Well worth it, main thing is you have to be careful about blowing smoke. Running a bottle of fuel booster helps cut down on the smoke.

Im not expecting good mileage! I just want medeocre gas mileage!! Diesels are easily capable of getting 15+ mpgs!

New ones are, when they're left stock. But you shouldn't expect that when you lift it and put huge tires on it. I just came back to Dallas from Arkansas and got 15+ with a load in the back, completely stock.

Bottom line, you bought a large truck and then lifted it sky high with big tires. What else were you expecting? If you are that concerned with mpgs then sell the truck and get something more economical and leave it stock.

THIS

What the hell did you expect? Want good gas mileage go buy your *** a prius

wait till the high pressure fuel pump goes out and ford denies the warranty. you have to rebuild the whole fuel system because of metal contamination and sometimes it hangs an injector open and blows a rod out the side. seen it several times.